Review Questions Exam # 3 Flashcards
How can you diagnose neosporosis in cattle? What are your options?
◦ Immunological (ELISA) and molecular tests for ruminants
◦ Antibodies in bulk milk
◦ Organism in abortus (CNS, muscle - bradyzoites)
◦ Clinical and epidemiological appearance (abortions mid-gestation)
How can you diagnose Eimeria infection in ruminants?
◦ Clinical signs/ history - may appear before oocysts are shed. (diarrhea (bloody/ mucous), history of stress, cold snap, dehydration, pale congested mucus membrane, prolapse of rectal membrane
◦ Fecal exam - fecal flotation
What is the disease/complex caused by a large number of GI nematodes?
◦ Parasitic Gastroenteritis (PGE)
Name the surface and burrowing mites commonly found in ruminants.
◦ Surface: Chorioptes sp., Psoroptes sp.
◦ Burrowing: Scarcoptes sp., Demodex sp.
What are the main clinical signs of haemonchosis in small ruminants?
◦ Clinical signs: Anemia in sheep and goat ( both adults and larvae suck blood). Severe clinical disease in sheep goat, camelids, exotic hoofstock ( death). In older cattle it contributes to PGE.
◦ Anemia, submandibular edema (hypoproteinemia)(bottle jaw) death is common.
What is the best time to treat for lice?
◦ Treat in fall before the louse burdens increase.
What is the role of ruminants in the lifecycle of Taenia saginata and Echinococcus granulosus?
◦ Ruminants are intermediate hosts for both of these parasites.
When you see thick scabby crusts, often having coagulated exudates and intensely pruritic
papules on sheep’s bodies, which mite species might be causing this?
◦ Psoroptes
Infection of which fluke results in calcified bile ducts or Pipestem liver?
◦ Fascicola hepatica
Why are cysticercus bovis and hydatid cysts more of a concern to us? What is the role of humans
in the lifecycle of these parasites?
◦ Humans are definitive hosts for cysticercus bovis - Humans infected by eating infected meat. Cattle contaminated by ingesting infected human feces/ being in contact with human feces.
◦ Humans are intermediate hosts for hydatid cysts. Larval stage of Echinococcus. All species can get larval stage. Can be fatal for humans ( cysts occur in tissues, if it occurs in liver or heart it can be fatal)
What are the slow dividing tissue cysts of systemic apicomplexa called? What are tachyzoites?
◦ Bradyzoites are the slow dividing cysts usually found in muscle of IH. Tachyzoites are the fast dividing cysts ( usually those that are spreading from definitive host to intermediate hosts)
How do you diagnose Fasciola hepatica infection in cattle?
◦ Detection of characteristic eggs in feces,
‣ Large, golden brown, operculated and heavy. Use sedimentation technique, use fluke finder. Also use clinical signs and history
What is unique about the lifecycle of Dicrocoelium dendriticum?
◦ Peculiar life cycle, land snails and ants intermediate hosts. Fluke hijacks brain of ant and makes them stand on plan without movement waiting to be eaten.
How is the lifecycle of protostrongylid lungworms different from general ruminant lungworms?
◦ General ruminant lung worms have direct lifecycle, while protostrongylus is an indirect life cycle with Gastropod intermediate hosts.
Main clinical signs associated with brain worm infection in ruminants?
◦ Clinical signs:
‣ White tail deer: none
‣ Abnormal hosts: ataxia, listlessness, fearlessness, unable to feed/ forage, lameness, weakness, blind/deaf , circling, head tilt/ abnormal neck position, emaciation, paralysis.
Advise on which animals to treat for different mite infestations?
◦ Choroiptes - contagious among different species.
◦ Demodex - not contagious Treat affected one.
◦ Psoroptes - contagious among one species.
◦ Scarcoptes - Just same species.
Are cattle fever ticks one host tick or three-host ticks?
◦ 1 host tick
On necropsy, where do you expect to find adult Dictyocaulus?
◦ Inflammation due to presence of aspirated eggs and larva in bronchioles and alveoli.
When (which season) is lice problem more common?
◦ common in the winter
What is a winter tick? General lifecycle?
◦ Dermacentor albipictus - 1 host tick.
◦ Life cycle: Finds host in fall ( larva climb onto plants and wait for hosts to pass by -> larva to nymph on the host ( sept/ november) -> nymph to adult (october to feb) -> adults feed and mate (feb- march)-> The fed and bred female falls to the ground ( march - april) -> Eggs are laid ( june) -> cycle repeats
What is the common name for Oesophagostomum?
◦ Nodular worm
• Name the common chewing and sucking lice of ruminants.
◦ Chewing Lice: Damalinia (Bovicola) spp.
◦ Sucking Lice: Haemtopinus spp, Linognathus vituli, Solenoptes capillatus
Which protozoa is transmitted sexually in ruminants?
◦ Tritrichomonas foetus
Know the morphology of Demodex mite
◦ Morphology : Elongated with short stumpy legs, cigar looking.
Which mite is highly contagious among different species of animals? Which is contagious among
the same species and which is noncontagious?
◦ Choroiptes - contagious among different species.
◦ Demodex - not contagious
◦ Psoroptes - contagious among one species, scarcoptes
Modes of transmission of ruminant hookworm?
◦ Transmitted via ingestion of L3 or Percutaneous penetration by L3
What is the common name for Haemonchus?
◦ The barber pole worm
What is the site of infection of Haemonchus, Ostertagia, Cooperia, Bunostomum, Trichuris, and Oesophagostomum?
◦ Haemonchus: abomasum
◦ Ostertagia: abomasum
◦ Cooperia: Small intestine
◦ Bunostomum: small intestine
◦ Trichuris: large intestine
◦ Oesophagostomum: large intestine
re the crypto oocysts shed by cattle immediately infective?
◦ Oocysts shed are immediately infective
now the general morphology of the Nematodirus egg. How is it different compared to other
strongyle eggs?
◦ Eggs with smooth thin eggshell. Has two to eight large dark blastomeres separated from the yolk membrane by large fluid filled cavity. Much larger eggs than other trichostrongyles.
Besides the small intestine, where can you see Thysanosoma adults? Why is this important?
◦ Can be found in bile and pancreatic ducts. Can block bile ducts and cause digestive disturbances. Also cause an economic loss due to condemnation of livers after slaughter.
How can you diagnose Tritrichomonas foetus infection in cows and bulls?
◦ Cows: Microscopy and/or culture of cervical mucous, uterine fluids (aborting cows), Abortus: Stomach fluid
◦ Bulls: - Preputial scrapping (or washes) - Repeated sampling (3 tests at weekly intervals
◦ You can also do culture and PCR or direct PCR ( higher sensitivity than culture alone)
What are your two best pieces of advice to control brainworm transmission in domestic
ruminants?
◦ Reduce exposure to gastropods
◦ Deworming during peak transmission months ( late summer, fall) can reduce larval infections.
◦ Fences and other barriers around pasture.
Which parasite is commonly referred to as a Ruminant lungworm?
◦ Dictyocaulus Spp
Do you need to treat all animals (sheep, goats, horses) on the farm if you detect lice problems in
any one animal/species?
◦ Only treat the same species. Species specific parasite. You must treat the whole herd of the same species thought, since it is highly contagious.
What is the common liver fluke of ruminants?
◦ Fasciola hepatica
What is the common name for Ostertagia?
◦ Brown stomach worm
Which ruminants are most severely affected by giant liver fluke and why?
◦ Sheep the extensive, uninterrupted hepatic migration, without encapsulation, usually fatal, even 1 fluke.
What is the spinose ear tick? How is it different from the Asian longhorn tick?
◦ It is a soft tick ( asian long horn tick is a hard tick) It is also a 1 host tick ( asian longhorn tick is 3 host tick) Spinose ear ticks also have just larva and nymphs parasitic and adults are free living, asian longhorn ticks are parasitic at each life stage.
Do Demodex mites transmit between animals? Do they cause severe itching?
◦ No it does not transmit. No pruritis is absent
What is the predilection site for Tritrichomonas foetus in cows and bulls?
◦ Bulls: Protozoa hides within the crypts of the prepuce ( deeper in older bulls)
◦ Cows: Vaginal mucosa
What is the shed/diagnostic stage of Dictyocaulus? Which test do you use to diagnose?
◦ Shed: L1!! L1-L3 in the environment
◦ Diagnostic Stage: L1
- Infective L3
◦ Test: baerman
What is the general pathophysiology of ostertagiasis in ruminants? What happens in the abomasal glands, and what is the result?
◦ Developing larvae produces small nodules on abomasa surface. ( larvae is developing within the gastric glands) Significant effect when parasite emerge from gastric glands ( they destroy the gastric glands, disrupt acid base balance, causes inflammation, ect)
‣ Normal Gastric Gland:
• Zygomen glands (on bottom) produce pepsinogen.
• Parietal glands secrete HCl. HCl will convert Pepsinogen to pepsin to break down food.
• No gaps between gland epithelium.
‣ Damaged Gastric Gland:
• Widening of gaps between cells cause hypoproteinemia from protein leaking into gut lumen from the plasma.
• Damaged epithelial cells are replaced by undifferentiated cells, so pepsinogen has nothing to convert it.
• Pepsinogen will leak into plasma ( since there is larger gaps) and pepsin is not produced/ produced very mildly. This causes the gastric pH to increase.
• Increased in pH / lack of pepsin will disrupt the digestive function of the abomasum (malnutrition) and overall there is less availability of nutrients to the animal.
◦ ◦ In a nut shell:
◦ ‣ PH increases, less breakdown of food + diarrhea
◦ ‣ High pepsinogen in plasma
◦ ‣ distention/ widening of gland.
What are the main risk factors for Strongyloidiasis in cattle?
◦ High environmental temperature, humidity. Larval develops within a day which allows for continuous transmission (hyperinfection) Sawdust is common in all outbreaks.
Which protozoal species are the most important cause of abortions in large ruminants and small
ruminants?
◦ Neospora caninum - dairy cattle
◦ Toxoplasma gondii - sheep and goats
What are the roles of deer, cattle, and sheep in the epidemiology of giant liver fluke?
◦ Cattle and moose are dead end hosts : flukes walled off in liver parenchyma, no eggs are shed, no clinical signs, diagnosed at slaughter house typically.
◦ Sheep, Goat, camelids: Also dead end hosts, but have more severe damage.
‣ Sheep the extensive, uninterrupted hepatic migration, without encapsulation, usually fatal, even 1 fluke.
Which is the most important parasite of stocker cattle in the US?
◦ Cooperia spp.
Explain the general lifecycle of brainworm and the role of white-tailed deer and other ruminants
in the lifecycle.
◦ White tail dear ingests slugs and causes larva to develop into adults, lifecycle complete and repeats.
‣ If other hosts ingest slugs, L3 released in intestines, L3 digestive tract. Travels along spinal nerves/ spinal cord to brain. Causes severe neuro disease. In non natural hosts, larvae does not develop into adults, hence no larval shed in feces.
‣ White tail deer maintains lifecycle, no signs
Which nematode species can cause cyst-like structures at the bases of hair follicles, especially in
the ventral midline and on the flanks, udder, teats, face, and neck? How is this parasite transmitted to another host?
◦ Parasite: Stephanofilaria
◦ Fly ingests Microfilaria from dermis of infected animal -> in fly develops to L3, introduced L3 develop into adults in hair follicles.
